This invention relates to an improved structure for a water filter outer shell, specially relating to an improvement that has lower costs of production.
The known water filter outer shell structure consists of a flange position on the exterior wall near the tubular opening conical wall surface with an O-ring seated against the conical surface of the interior wall by a top cover over the upper extend of the outer shell. There is an exterior thread formed along the outer wall of the aforesaid top cover as well as a sleeve that has a matching inner thread and which can be inserted on the outer shell and further screwed onto the top cover. The inner lip at the lower edge of the sleeve tightly secures the top cover to the outer shell as well as produces an interior generated binding force secured outward to the outer shell, increases the internal resistance pressure of the outer shell. This, therefore, reduces the tubular wall thickness of the outer shell and, furthermore, increases the water permeation seal.